1. Open a Contact Sheet for the folder, and select all the images. (command-a on Mac, ctrl-a on Windows)
2. Open an IPTC Metadata template (command-i on Mac, ctrl-i on Windows)
3. Scroll down to the Media section and click the Data Mining checkbox and select an option from the dropdown. (Note: if you have used the template previously, you may want to click "clear" first to clear out any other values which have persisted from last use)
4. Click "Apply Template to Selected"
